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HYDROCYANIC ACID IN PLANTS, 11., 



Bouteloua oligostachya. — This Mexican prairie grass is growing 

 in the neighbourhood of Tenterfield, and specimens from there 

 growing in the Botanic Gardens, were found, at certain seasons, to 

 react strongly for glucoside. In the autumn it entirely dis- 

 appeared, to return again faintly in the rainy season, and 

 gradually to increase in the Spring, to a maximum at Mid- 

 summer. 



January ... + very strong. August ... + faint. 



April ... - November ... + strong. 



Chloris. — Four specimens of this grass are cyanophoric; of these 

 two are native to N.S.Wales, viz., C. truncata and C. ventricosa, 

 and are widely distributed over the Eastern States. 



The exotic species, from which positive results were obtained, 

 are C. petrcea and C. polydactyla, and are cultivated in the 

 Botanic Gardens. 



C. truncata 

 C. ventricosa .. 

 G. petrcea 

 G. polydactyla. 



January. 



+ strong 

 + strong 

 + faint 

 + very strong 



April. 



+ faint 



+ very strong 



August. 



+ faint 

 + faint 

 + very strong 



November. 



+ faint 



+ very strong 



+ very strong 



Samples of the native species were collected by Mr. Breakwell in 

 Narrabri, Wagga, and Coonamble districts, from September to 

 December, and these all gave, during this season, negative results. 



Cortaderia argentea. — The three varieties, gigantea, rosea, varie- 

 gata, growing in the Botanic Gardens, were tested, and also a 

 number of specimens growing elsewhere in Sydney. All gave 

 "strong" reactions in all seasons. 



Cynodon incompletus. — This blue couch-grass is recorded only 

 from E. and S. Africa, and in New South Wales from the Upper 

 Hunter River and Forbes. It is still doubtful whether it has been 

 introduced from S. Africa or is indigenous to Australia (Maiden, 

 Agric. Gaz. N.S.Wales, 1912, 295). 



Hydrocyanic acid was first detected in this grass in November, 

 1911, in a patch cultivated in the Botanic Gardens, and which had 



